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TI-2026-75346 Aliases CVE-2026-54657

Open Zaak search endpoints return case metadata beyond token scope

Priority LOW 28CWE-285Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-285.

Summary

Open Zaak from 1.0.0 before 1.27.2 and from 1.28.0 before 1.28.2 has an authorization flaw in its POST search endpoints for cases and documents. The endpoints do not filter results by the authorizations linked to the request token (CWE-639). A caller with a valid zaken.lezen or documenten.lezen token can retrieve case or document metadata outside the token's authorized types or confidentiality levels. Document searches require known UUIDs, and document content stays protected by separate download authorization.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Open Zaak is an open-source data and services layer for Dutch case-oriented working. From 1.0.0 until 1.27.2, 1.28.2, and 1.29.0, the POST search endpoints /zaken/api/v1/zaken/_zoek and /documenten/api/v1/enkelvoudiginformatieobjecten/_zoek do not filter result querysets according to the authorizations associated with the request token. A caller with a valid zaken.lezen or documenten.lezen token can therefore retrieve case or document metadata outside the token's authorized types or confidentiality levels. Document searches require known UUIDs, and document content remains protected by separate download authorization. This issue is fixed in versions 1.27.2, 1.28.2, and 1.29.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00263 18th percentileScored 2026-11-07
Fix Fixed open-zaak (open-zaak): 1.27.2, 1.28.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
open-zaakopen-zaak1.0.0 to before 1.27.2; 1.28.0 to before 1.28.21.27.2, 1.28.2Patch availableCNA
  • open-zaak Vendoropen-zaak Affected 1.0.0 to before 1.27.2; 1.28.0 to before 1.28.2 Fixed in 1.27.2, 1.28.2 Patch available CNA

Remediation

Upgrade Open Zaak to version 1.27.2, 1.28.2 or 1.29.0.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA open-zaak (open-zaak) Fixed in 1.27.2, 1.28.2

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-54657
  2. 2026-10-16 CISA SSVC decision points changed
  3. 2026-10-16 Priority changed: MEDIUM → LOW

References

Other 7

  • TI-2026-75348 Path traversal in Open Zaak lets clients read server files CVSS 3.1MEDIUM 6.8
  • TI-2020-16072 CORS configuration is possibly vulnerable CVSS 3.1MEDIUM 4.7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences